Theresa Boi Ngoc Nguyen, OD
Optometrist · Merced, CA
Theresa Boi Ngoc Nguyen, OD is an optometrist with a practice address in Merced, California, and NPI 1437896180, issued on May 15, 2022. Check the license (California 35123, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Theresa Boi Ngoc Nguyen
- Credential
- OD
- Primary taxonomy
- Optometrist 152W00000X
- License number
- 35123 CA
Self-reported in NPPES; status is on the state search - Practice location
- 3178 Collins Dr Ste A, Merced, CA 95348
- Phone
- (209) 383-1246
- Enumerated
- May 15, 2022
- Record last updated
- May 15, 2022
- Medicare enrollment
- Enrolled (PECOS I20220921003602); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest optometrist records → All 8,308 in California → Look up another NPI →
Also registered at 3178 Collins Dr Ste A
A shared address usually means a shared clinic or building; it does not show who employs whom.
- David BabaOptometrist1427011345
Verify Theresa Boi Ngoc Nguyen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 35123Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Industry payments in 2024: $218.62
9 payments; by number, the most common kind was food and beverage; the largest payer was Alcon Vision LLC. The 34,453 providers of this specialty with any payment received $769.99 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Johann J Schlager OD IncMerced, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Theresa Boi Ngoc Nguyen among 8,308 optometrist records in California
Theresa Boi Ngoc Nguyen, OD is one of 8,308 optometrist records with a practice address in California. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2022, is newer than 89% of them.
- NPI issued2022 · 89% of these records are older, 8% newer
- In a Medicare fileYes · 67% of these records are
- In the CMS Doctors and Clinicians fileYes · 43% of these records are
- Graduated2021 · median 2008 among the 3,573 with a school on file
- Record last updated2022 · 67% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 152W00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
22 optometrist records list a practice address in Merced
They are 22 of the 2,836 NPPES records with a practice address in Merced, and 8,308 optometrist records in California.
All 8,308 in California → Every provider in Merced → Optometrist nationwide →
The 8 optometrist records with the nearest ZIP codes
- David BabaMerced, CA 953481427011345
- Eduardo Cruz-Aragon, ODMerced, CA 953481689447633
- Dennis Hartman, O.D.Merced, CA 953481922078294
- Kellee Meyer, O.D.Merced, CA 953481942366240
- Neil Nebeker, O.D.Merced, CA 953481679566020
- Katherine Ngo, ODMerced, CA 953481245025816
- Paul Smith, ODMerced, CA 953481912937251
- William Springer, O.D.Merced, CA 953481407396138
Common questions
What is Theresa Boi Ngoc Nguyen, OD's NPI number?
Theresa Boi Ngoc Nguyen, OD's National Provider Identifier (NPI) is 1437896180, issued on May 15, 2022. An NPI identifies a provider in billing; it is not a license.
Where is Theresa Boi Ngoc Nguyen, OD located?
The NPPES record lists a practice address at 3178 Collins Dr Ste A, Merced, CA, 95348. Phone: (209) 383-1246. Providers update this record themselves, so call before visiting.
How can I verify Theresa Boi Ngoc Nguyen, OD's license?
NPPES lists California license number 35123, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.